ISO 3744

Sound power โ€” enveloping surface engineering method

ISO 3744 specifies the engineering method for determining sound power and sound energy levels using sound pressure measurements obtained on an imaginary surface (hemispherical or parallelepiped) surrounding a noise source. This method is widely used for in-situ testing of machinery, industrial equipment, and large installations where reverberation room testing is impractical. It provides a practical balance between accuracy and field applicability, making it suitable for machinery compliance testing, environmental noise assessments, and product CE marking requirements across the EU. ISO 17025 accreditation confirms laboratory proficiency in sound field measurement, environmental parameter correction, and uncertainty quantification for this complex measurement method.

What it measures

  • Sound power level (Lw) using enveloping surface pressure data
  • A-weighted and frequency-weighted sound power
  • Octave and one-third-octave band sound power (63 Hz to 8 kHz)
  • Environmental and measurement corrections
  • Sound power directivity and spatial variability
๐Ÿ‡ฉ๐Ÿ‡ช DIN EN ISO 3740 ๐Ÿ‡ฌ๐Ÿ‡ง BS EN ISO 3740 ๐Ÿ‡ซ๐Ÿ‡ท NF EN ISO 3740 ๐Ÿ‡ฎ๐Ÿ‡น UNI EN ISO 3740 ๐Ÿ‡ช๐Ÿ‡ธ UNE EN ISO 3740 ๐Ÿ‡ณ๐Ÿ‡ฑ NEN EN ISO 3740 ๐Ÿ‡ฉ๐Ÿ‡ช DIN EN ISO 3743-1 ๐Ÿ‡ฌ๐Ÿ‡ง BS EN ISO 3743-1 ๐Ÿ‡ซ๐Ÿ‡ท NF EN ISO 3743-1 ๐Ÿ‡ฎ๐Ÿ‡น UNI EN ISO 3743-1 ๐Ÿ‡ช๐Ÿ‡ธ UNE EN ISO 3743-1 ๐Ÿ‡ณ๐Ÿ‡ฑ NEN EN ISO 3743-1
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Industries

Industrial machinery manufacturers Construction equipment producers HVAC and ventilation systems Power generation and compressor suppliers Large transport and handling equipment makers

Related Standards

  • ISO 3740 Acoustics โ€” Determination of sound power levels of noise sources โ€” General guidelines
  • ISO 3743-1 Acoustics โ€” Determination of sound power levels of noise sources โ€” Part 1: Reverberation room method
  • ISO 3745 Acoustics โ€” Determination of sound power levels of noise sources โ€” Precision method using an enveloping surface

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